By Mark Lamport-Stokes LOS ANGELES - The Los Angeles Dodgers appointed longshot Dave Roberts as their new manager on Monday, a month after the club had mutually agreed to part ways with the previous skipper, Don Mattingly. Roberts, 43, was the starting center fielder for the Dodgers from 2002-04 but has never previously managed at any level in baseball. Most recently, he was bench coach with the San Diego Padres and he takes charge of one of the sport's best-known franchises after dazzling the club's management in his interview.